Question

7. If the area of the circle is 154 sq. cm, then find its diameter.​

Answer 1

Answer:

Area of the circle = πr2

22/7 ×r 2

=154

r=7cm

Circumference of the circle=2πr=22/7× 7×7=44cm

Answer 2

To find : diameter of circle .

Given : area of circle is $154\ cm^{2}$

Solution :

• As per given that we know that area of circle is $154\ cm^{2}$.We are asked to find diameter of circle .
• We use following formula to find area of circle , using this formula we find find radius of circle by substituting the given values .
• Area of circle = $\pi r^{2}$  

       $154 = \frac{22}{7} \times r^{2}$  

       $r^{2}= \frac{154\times 7}{22} \\r^{2} = 49\\r = 7\ cm$

• Now , as we know that diameter is twice of radius , therefore we write as , diameter = $2r$

                               $=2\times 7 \\=14\ cm$  

Hence , diameter of circle is $14\ cm$ .